All of you, the company will not keep track of your dates for pay, let alone if it goes long enough to get a bump out of it.
Keep track of bidders that are trained junior to you, and the effective dates of the bid. You might be able to get pay protection out of the deal. That way you get paid the higher rate, and bid your current seniority and hours. Pretty nice deal.
Unless you squawk about it, you'll not get paid. I consider this yet another area the company willing violates the contract on a daily basis.